Ultrasonic method for establishing and maintaining a liquid suspension delivery system that prevents the dispersed particles from precipitating out of suspension

ABSTRACT

The present invention relates generally to a method and apparatus for applying wave energy of an ultrasonic frequency to agitate particles in a sample. The agitated sample is then delivered via a syringe or a resonating syringe plunger attachment of an applicator. More particularly, the present invention relates to establishing and maintaining a liquid suspension delivery system that prevents dispersed particles from precipitating out of suspension while the sample is delivered through to various applicators, such as resonating syringe plungers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. Provisional Patent Application Ser.No. 61/041,853, titled “Ultrasonic Method for Establishing andMaintaining a Liquid Suspension Delivery System That Prevents TheDispersed Particles From Precipitating Out of Suspension,” filed Apr. 2,2008, the disclosures of each which are hereby incorporated by referencein their entirety.

FIELD OF THE INVENTION

The present invention relates generally to a method and apparatus forapplying ultrasonic frequency wave energy to agitate particles in asample. More particularly, the present invention relates to establishingand maintaining a liquid suspension delivery system that preventsdispersed particles from precipitating out of suspension whiledelivering the material to various devices, such as resonating syringeplungers and syringes.

BACKGROUND OF THE INVENTION

Scientists, technicians and others often have problems deliveringprecise proportions of materials (solutes) in a suspension liquid to asurface. They have discovered inconsistent mixture ratios bring abouthigh waste when solutes come out of suspension. For example, asuspension in a barrel of a syringe applicator comes out of suspensionleaving unusable and undelivered material in the syringe. The scientistwill have to “waste” or dispose of this left over material. The materialmay be hazardous and thus time consuming and costly to dispose ofproperly.

Another problem faced with solution delivery mechanisms is unevendistribution of materials in the solution. For example, a 10 cc solutionin a delivery apparatus may have a higher concentration of solutes inthe lower elevations of a solution sample and a lesser concentration ofsolutes in the upper elevations of the solution sample. Therefore, asthe suspension is delivered or applied its concentration or ratio ofsolutes to liquid varies as it is delivered or applied to a surface.

A common technique to produce a solution is to utilize an ultrasonicmixing system and uses wave energy at the upper threshold of humanhearing, which starts at 20,000 hertz to mix and speed dissolution. Thisis achieved by breaking the molecular bonds in a solute and go into asolution. Additionally, this technique may provide energy needed forcertain chemical reactions to start.

A problem with current delivery techniques is the precipitation ofsuspended particles or coming out of solution immediately before thesolution is delivered. This occurs when the agitation or mixing isstopped and the solution is moved from the mixing or staging area to theapplicator. Therefore, what is needed is a system and a methodology tokeep the particles suspended as they are delivered.

SUMMARY OF THE INVENTION

The present invention relates generally to a method and apparatus forapplying sound energy to agitate particles in a sample with anultrasonic resonating syringe plungers that pushes a liquid solutiontowards said syringe's exit. Therefore, a solution is both agitated anddelivered from within the syringe. More particularly, the presentinvention relates to establishing and/or maintaining a liquidsuspension, in a delivery system that prevents dispersed particles fromprecipitating out of suspension while the sample is delivered to varioustypes of applicators.

An embodiment has a syringe applicator devise composed of a glass and/orsteel outer body with a titanium and Teflon resonating syringe plunger.The solution is extruded out by engaging the resonating syringe plunger.The resonating syringe plunger incorporates resonant transducers thatoperate in ultra-sonic frequency range of 20,000 to 120,000 Hz. to mixand agitate the solution.

In an embodiment, an ultrasonic suspension delivery device is disclosed.It comprises a solution delivery device with an ultrasonic pushingassembly with a horn agitator assembly and at least one power connectorto receive power from an ultrasonic energy source. It has a barrel withat least one liquid intake and outtake port; and said barrel with anadditional opening permitting said solution delivery device ingress andegress, while hydro dynamically sealing ultrasonic pushing assembly fromsaid horn agitator assembly.

In an additional embodiment, portions of the device are made out oftitanium or stainless steel. For example, the ultrasonic pushingassembly and/or the horn agitator assembly. The horn agitator can alsobe made from a ceramic material.

In yet another embodiment, the ultrasonic energy source operates in thefrequency range of 20,000 to 120,000 Hz. providing a multitude ofoptions to find an optimal agitation frequency of a solution.

In an embodiment, the barrel is made out of glass or plastic, permittingdisposability, interchangeability and the opportunity to use the leastreactive material to hold the solution.

In an additional embodiment the barrel can accommodate a needle or acannula delivery system. Thus it can be adapted to various uses,depending on the requirements. For example, when coating a surface of asilicon wafer, the user may wish to use a cannula with an atomizingsprayer.

In an embodiment, the device can use a SubMiniature version A (SMA)coaxial connector or a twisted pair cable with a Euro style M12connector instead of being hardwired to the ultrasonic power source,thus permitting transducer interchangeability. One device can be usedwhile a second one is being cleaned or serviced.

There has thus been outlined, rather broadly, certain embodiments of theinvention in order that the detailed description thereof herein may bebetter understood, and in order that the present contribution to the artmay be better appreciated. There are, of course, additional embodimentsof the invention that will be described below and which will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of embodiments inaddition to those described and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein, as well as the abstract, are for thepurpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a simple hand-powered piston syringe.

FIG. 2 illustrates a simple piston pump plunger component of an ordinarysyringe.

FIG. 3 is a side perspective view of the ultrasonic suspension syringeplunger to be used in combination with a syringe vessel.

FIG. 4 is a side perspective view of the ultrasonic piston pump plunger.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to a method and apparatus forapplying wave energy of an ultrasonic frequency to agitate particles ina sample. The agitated sample is then delivered from the syringe vesselto the target applicator, usually a resonating syringe plunger. Moreparticularly, the present invention relates to establishing andmaintaining a liquid suspension delivery system that prevents dispersedparticles from precipitating out of suspension while the sample isdelivered to various applicators.

A simple hand-powered piston syringe pump is illustrated in FIG. 1,consisting of a lower piston plunger 4 a and an upper piston plunger 4 bthat can be pulled and pushed inside a cylindrical tube 5 (the barrel),which has a small hole 3 on one end. The syringe draws a liquid in andthen extrude it out through the small hole 3. A needle 6 or cannuladelivery mechanism is affixed at the top of the cylindrical tube 5. FIG.2 illustrates another type of simple piston pump plunger 2.

To deliver a suspension liquid with this type of delivery systems, theuser would first prepare a solution and draw it up through the smallhole 3 by retracting the lower plunger 4 a and an upper plunger 4 bassembly. Once the desirable amount of suspension liquid is in thecylindrical tube 5, the user can then push the lower plunger 4 a and anupper plunger 4 b assembly into the cylindrical tube 5 forcing theliquid out the small hole 3. Small hole 3 can have a needle 6 or anatomizing spraying assembly (not shown) affixed to the cylindrical tube5.

A first embodiment is shown in FIG. 3. A cylindrical tube (barrel) 10 ismade out of glass. It should be noted that the cylindrical tube (barrel)10 can be made from any hard material, such as titanium, aluminum,stainless steel, plastic or any material with no or little reactiveproperties. Power is connected to the ultrasonic resonating syringeplungers 12 by power cable 14 to a negative terminal 16 and a positiveterminal 18. The ultrasonic resonating syringe plungers 12 employ highfrequency sound waves, those beyond the range of human hearing. It hasone or more piezoelectric transducers 32 to convert electrical energyinto mechanical energy. The piezoelectric transducers 32 receiveelectrical input in the form of a high frequency signal from a powergenerator and convert that into vibratory motion at the same frequency.

The resonating syringe plungers are configured such that excitation ofthe piezoelectric transducers creates a transverse standing wavesomewhere along the length of the ultrasonic resonating syringe plungers12. For ultrasonic energy to be effective for atomization the atomizingshould take place at an anti-node. The ultrasonic resonating syringeplungers 12 is selected such that an anti-node is located within itselfor within the horn agitator 23. For example, the anti-node of thestanding wave can be located at the base of horn agitator 23, as shownby surface 18 of FIG. 4. causing the horn agitator 23 to vibrate andagitate the solution. The anti-node's location can be adjusted byfrequency selection to accommodate the characteristics of the solute andof the suspension liquid. For example, the user may wish to place theanti-node at the midpoint of the horn agitator 23. This can beaccomplished by frequency selection or selecting a different length forthe ultrasonic resonating syringe plungers 12, or both.

In general, high frequency resonating syringe plungers are smaller,create smaller drops, and consequently have smaller maximum flowcapacity than resonating syringe plungers that operate at lowerfrequencies. The speed of sound in air is 340 m/s and using a 34,000 Hz.acoustic signal, the wavelength of one sound wave is 340 m/s divided by34,000, which is equal to 10 millimeters. A half-wave would be 5millimeters. Therefore the length of the ultrasonic resonating syringeplunger's 12 length should be 5 millimeters. A 68,000 Hz. would have awavelength of 5 millimeters and a half wavelength of 2.5 millimeters.The above examples were done for air at sea level and values will varygreatly with differing liquids.

It should be noted that the ultrasonic resonating syringe plungers 12 isoptimally composed of titanium. Titanium is chosen due to its hightensile strength to density ratio, its high corrosion resistance, andits ability to withstand moderately high temperatures without creeping.Any other material with the similar characteristics as titanium may,also be chosen to become ultrasonic resonating syringe plungers 12.

An grounding location is provided by ground screw 20. The rear of theplunger 22 does not necessarily have to be made of titanium, forexample, it can be nylon, Teflon or any other hard material that beaffixed to the ultrasonic resonating syringe plungers 12. The plungerfront 26 which is affixed to the plunger assembly 12 via threads and maybe further sealed with an epoxy. The plunger front 26 can be made ofTeflon, nylon or any other material that will not react with the liquidsolution 28. An o-ring 25 further ensures a seal between the plungerfront 26 and the ultrasonic resonating syringe plungers 12. A liquidseal 27 is made by shaping the plunger front 26 and its positioningagainst the cylindrical tube (barrel) 10 producing a dynamic seal. Thesuspension liquid 28 is drawn into the ultrasonic syringe and isextruded through the opening 30.

In operation, a low power alternating current (AC) is applied to theultrasonic resonating syringe plungers 12 causing a transducer to becomeexcited. The transducer is coupled to the transducer horn agitator 23and begins to vibrate and agitate the solution 28. The energy for thetransducers is supplied by an ultrasonic generator (not shown).

Referring to FIG. 4 which shows an additional embodiment, the resonatingsyringe plunger power cable 14 terminates with at a SubMiniature versionA (SMA) 8 coaxial connector or any other efficient coaxial or twistedpair connector, such as or a twisted pair cable with a Euro style M12connector. The ultrasonic resonating syringe plungers 12 has thematching SMA connector on it allowing the present invention to beconnected to a ultrasonic generator via interchangeable coaxial cablefacilitating uncomplicated swapping of transducers and ultrasonicgenerators.

The many features and advantages of the invention are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the invention which fallwithin the true spirit and scope of the invention. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the invention to theexact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

1. An ultrasonic suspension delivery device, comprising: a barrelincluding a proximal opening and a distal opening coupled to a deliverymechanism; and an ultrasonic resonating syringe plunger, slidinglydisplaceable within the barrel for pushing a liquid toward the distalopening of the barrel, including: a front body including a boreextending completely therethrough, and a seal, disposed along the outercircumference of the distal end, to engage the inner surface of thebarrel, a rear body including a bore extending partially therethrough, aproximal end having a transverse plunger surface, and a distal endattached to the proximal end of the front body, a transducer disposedwithin the bore of the rear body, a horn agitator, disposed within thebore of the front body, rigidly coupled to the transducer andresiliently coupled to the front body, and at least one power connector,coupled to the transducer, to receive power from an ultrasonic energysource.
 2. The ultrasonic suspension delivery in claim 1, wherein thefront body and the rear body of the ultrasonic resonating syringeplunger are made from titanium.
 3. The ultrasonic suspension delivery inclaim 1, wherein the front body and the rear body of the ultrasonicresonating syringe plunger are made from stainless steel.
 4. Theultrasonic suspension delivery in claim 1, wherein said horn agitator ismade from titanium.
 5. The ultrasonic suspension delivery in claim 1,wherein said ultrasonic energy source operates in the frequency range of20,000 to 120,000 Hz.
 6. The ultrasonic suspension delivery in claim 1,wherein said barrel is made out of glass.
 7. The ultrasonic suspensiondelivery in claim 1, wherein said barrel is made out of plastic.
 8. Theultrasonic suspension delivery in claim 1, wherein the deliverymechanism is a needle or a cannula.
 9. The ultrasonic suspensiondelivery in claim 1, wherein said at least one power connector is aSubMiniature version A (SMA) coaxial connector.
 10. The ultrasonicsuspension delivery in claim 1, wherein said at least one powerconnector is a coaxial connector.
 11. The ultrasonic suspension deliveryin claim 1, wherein the horn agitator is resiliently coupled to thefront body using an O-ring.
 12. The ultrasonic suspension delivery inclaim 1, wherein, in operation, the transducer generates a standing wavethat has an anti-node located at the proximal base of the horn agitator.13. The ultrasonic suspension delivery in claim 1, wherein, inoperation, the transducer generates a standing wave that has ananti-node located at the midpoint of the horn agitator.